Abstract:

Objective To investigate the effects of mesenchymal stem cells (MSCs) originated interleukin-6 (IL-6) on the nerve cells injury. Methods The rat siIL-6 recombinant lentivirus plasmid was constructed and the siIL-6 recombinant lentivirus was infected by MSCs. The MSCs cell line with stable siIL-6 expression was selected by puromycine. The variations of IL-6 mRNA and protein expression levels were detected by the Real-Time PCR and Western blotting. The secretion level of IL-6 was detected from the cultured supernatant of siIL-6-MSCs by the ELISA. The siIL-6-MSCs cells and PC12 cells injured by oxygen glucose deprivation (OGD) were separated and co-cultured. Cell apoptosis was detected by the Annexin V-FITC/PI. Expressions of key protein STAT3 of IL-6 signaling pathway and apoptosis related factors Bax and Bcl-2 were detected by the Western blotting. Results The IL-6 siRNA sequence was correctly cloned to the lentivirus plasmid. Expression levels of IL-6 mRNA and protein and the secretion level of IL-6 significantly decreased after MSCs were infected by the siIL-6 lentivirus. After being separated and co-cultured with siIL-6-MSCs, the apoptosis of OGD injured PC12 cells increased; protein expression levels of STAT3 and Bcl-2 significantly decreased; and the protein expression of Bax significantly increased. Conclusion MSCs-originated IL-6 may regulate the anti-apoptotic function of OGD injured PC12 cells through the STAT3 signaling pathway.

Key words: mesenchymal stem cells, interleukin-6, oxygen glucose deprivation, nerve injury, STAT3, anti-apoptosis